After each transfemoral angiographic procedure, it is always necessary to apply external pressure over the puncture site for a period ranging from fifteen to thirty minutes in order to stop the bleeding. Manual method has been the only means. In the market is a "Compressar" mechanical model which is basically a C-clamp device applying external but uncalibrated and uncalibrateable pressure over the puncture site. Ordinarily, pressure bandage or dressing devices are used after the bleeding has completely ceased. This invention discloses a more convenient, inexpensive, effort-saving, and labor-saving apparatus to stop the initial bleeding and any subsequent bleeding with external calibrated and calibrateable pressure from the plunger end of a pneumatically charged syringe assembly, as will be described more fully in the following specifications and further defined in the claims.